BBC News Graphics on Twitter: "GRAPH: How India's polio cases fell dramatically over the past three decades to zero today http://t.co/K6iCP3uBpU http://t.co/QzsQ6KzRg7" / Twitter
Graphical proof that vaccines work (with sources) | by Isabella B. | Medium
The U.S. Government and Global Polio Efforts | KFF
Polio incidence (solid line) plotted against the production in millions... | Download Scientific Diagram
Further Review: The Fight Against Polio | The Spokesman-Review